You may have noticed that the Moto X Pure Edition, Nexus 5X, and Nexus 6P all lack LTE Band 12. And, they do lack the band indeed… temporarily.

Considering the Nexus 6, a year ago, broke ground on supporting Band 12, there has to be another reason for the frequency being absent from these high-end devices.

As we mentioned in our last breaking article the real reason for T-Mobile demanding compliant VoLTE stacks on all devices bearing LTE Band 12. The reason is a planned VoLTE-only roaming agreement with US Cellular (read the exclusive here), one aimed at giving T-Mobile vastly superior voice and data coverage in rural markets, virtually overnight.

The only catch being, you must have an LTE Band 12 phone, and you must have a rock-solid VoLTE implementation that can cross carriers, for all voice phone calls. Oh, and E911 too… since a significant portion of T-Mobile’s rural map will actually consist of VoLTE-only roaming on US Cellular.

Android is very close to that, but not quite. Google has been working tirelessly to satisfy each carrier’s demands in the standard AOSP stack. For example, Verizon HD Voice 1.0 (their early VoLTE stack) for Nexus 6 phones. This is different from most Android Lollipop phones, which use an alternative app entirely when facilitating such calls.

Since Android Marshmallow will improve this, and it is launching with the Nexus 5X & 6P, it was not possible to achieve T-Mobile VoLTE certification – simultaneous with building new hardware, and a new generation of Android at the same time.

The gameplan here is pretty clear. Google will ship the LG Nexus 5X & Huawei Nexus 6P with Marshmallow, and then begin the work to certify their VoLTE with T-Mobile. This will almost certainly require an Android System update, and that update will unlock Band 12 simultaneously with VoLTE.

T-Mobile has confirmed that Wi-Fi calling will automatically enable itself, once a Nexus 5X or 6P is registered on the network, and that the carrier plans to sell both devices… indicating that T-Mobile is continuing its strong relationship with Google.

On the contrary, both AT&T and Verizon have indicated they do not intend to sell the Nexus 5X and 6P. This step back comes after a tumultuous relationship on both carriers with the Nexus 6 – which took nearly six months after launch, to ship on Verizon.

Furthermore, Nexus devices have run afoul of AT&T and Verizon’s ban on bootloader unlocks, even when the devices prominently alert the user that the bootloader has been disabled. PhoneNews.com has recommended (for years) that customers on AT&T and Verizon only use Nexus (or other carrier-free) devices, to protest this move. With the Nexus 5X returning Nexus phones to the sub-$400 price range, this is a viable recommendation once again.

PhoneNews.com Staff articles are typically in-depth articles. These are articles that involve multiple, and at times, several staff members who each contribute to the hard-hitting coverage that we deliver here.